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Sender: Arvind Sankar <niveditas98@gmail.com>
From:   Arvind Sankar <nivedita@alum.mit.edu>
Date:   Fri, 16 Oct 2020 10:16:26 -0400
To:     Borislav Petkov <bp@alien8.de>
Cc:     Arvind Sankar <nivedita@alum.mit.edu>, x86@kernel.org,
        Joerg Roedel <jroedel@suse.de>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 5/5] x86/head/64: Disable stack protection for
 head$(BITS).o
Message-ID: <20201016141626.GA1101574@rani.riverdale.lan>
References: <20201008191623.2881677-1-nivedita@alum.mit.edu>
 <20201008191623.2881677-6-nivedita@alum.mit.edu>
 <20201016111703.GD8483@zn.tnic>
 <20201016124301.GA1040839@rani.riverdale.lan>
 <20201016131545.GE8483@zn.tnic>
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On Fri, Oct 16, 2020 at 03:15:45PM +0200, Borislav Petkov wrote:
> On Fri, Oct 16, 2020 at 08:43:01AM -0400, Arvind Sankar wrote:
> > You need STACKPROTECTOR_STRONG -- I was testing with defconfig and the
> > option is enabled by default.
> 
> And you need to write those things in the commit messages.
> 
> Please, for the future, always make sure that all required ingredients
> for triggering a bug are documented in the commit message, before
> sending a fix. Jörg and I were both scratching heads on how you're
> reproducing this.
> 
> Thx.
> 

Sorry about that. This config option I didn't notice before since I
hadn't explicitly enabled the option, but I should have been more clear
about how I reproduced. I actually came across this from the other end,
was looking at the disassembly, saw the stack check call, and then spent
a while debugging why it did _not_ just always crash.

Thanks.